TronBiker: I have been using a magnetic tank bag. Have noticed however that it has left a white mark on my tank that I can't remove. I have heard using a rubber cover underneath can work.
Before I go trying it I'd love to know if anyone else also does this, before I do any further damage to my paintwork.
jaffa90: I use an imitation chamois leather, it¹s like a thin layer of sponge full of little holes.
Also, as you know, you should clean the magnet area from metal dust every time you fit it.
gsxr884: Or go to B&Q and buy the non-slip drawer liner stuff. It's just like the boot liner stuff that Halfords sell but a lot cheaper.
I use it on my tank (magnetic bag) and over my rear end to prevent pannier scuff.
GreenTea: Non-slip matting is available in lots of places, we use it in our motorhome. It can be expensive in caravan accessory shops, but cheap at steam rallies, markets stalls, etc.
Some is soft, other makes are harder. As it should stop any movement, it should stop any marking. Some have small holes, other types have larger holes and can be thicker. Go on eBay and search for 'anti slip mat caravan motorhome'.